The present invention relates to a method of heating or heating and reduction raw materials to be charged into a metallurgical furnace, utilizing high temperaure waste gases which are released from the metallurgical furnace, and to an apparatus therefor.
In the production of steels by use of metallurgical furnaces, such as a converter, iron ores are first reduced in a blast furnace with the combustion of coke to form molten pig iron. The pig iron is placed in a metallurgical furnace and oxygen is blown into the furnace to produce steels. Hereafter this process is referred to as blowing process. In the blast furnace, a large amount of coke is consumed to melt and reduce iron ores. For instance, coke ranging from 400 to 500 kg is required for melting and reducing 1 ton of iron ores. This amounts to the greater part of the energy required for the steel industries. In order to produce high quality steels, the temperature at the time of tapping thereof has to be controlled properly. In order to control the temperature, iron ore and other materials are charged as coolant into the converter.
During the blowing process, waste gases containing CO gas at the temperature ranging from 1400.degree. C. to 1600.degree. C. are released from the metallurgical furnace. The waste gases are caught by a cooling apparatus and scrubbed by a wet type scrubber and then released into the air or recovered in a gas holder.
Conventionally, when the scrubbing is performed by the scrubber, the CO gas are directly cooled by scrubbing water. Therefore, the heat of the gases is wasted.